Big T,
You say that you're not comparing the British Army with terrorists, but your comparisons tend to support the nationalist view of Bloody Sunday, and as such, they enrage me!
Northern Ireland is NOT South Africa, nor was it the USA during the Civil Rights era.
Irish Catholics and Nationalists were not an oppressed majority population. (They may have been discriminated against, but they were not a majority).
The British Army was an instrument of the legitimate, democratically elected government of the United Kingdom.
The legal route had not been exhausted at the time of Bloody Sunday, whereas it had been in the good old RSA.